Rapid 2D imaging enables two modes of motion to be distinguished. (A) Plots depicting xyz step sizes between each time point for three patches shown in Fig. 1 (F and G). Plot colors correspond to patch color in time-lapse images. (B) Trajectory of a single ZYG-12 patch followed at 400-ms intervals. Bold segments denote processive chromosome motions (PCMs). (C) Cumulative distance plot for the single representative trajectory shown in B. Green line shows step sizes observed between every five frames (2-s intervals). (D) Speed distribution of ZYG-12 PCMs. Green line shows fitted normal distribution. n = 91 PCMs. (E and F) Distributions of durations (E) and total displacements (F) of ZYG-12 PCMs. Green lines show fitted exponential decay; dotted lines show extrapolation to shorter times. (G and H) RMSD and MSD plots for PCMs, non-PCMs, and all trajectories. The limited duration of PCMs allows RMSD analysis up to only 8 s.